WHAT THE ARCHITECTURE IS
This section provides information about the system whose architecure is being documented, the relation of the views to each other, and an index of architectural elements.
This is a short prose description of what the system's function is, who its users are, and any important background or constraints. The intent is to provide readers with a consistent mental model of the system and its purpose. Sometimes the project at large will have a system overview, in which case this section of the architectural documentation simply points to that.
Mapping between Views
Since all of the views of an architecture describe the same system, it stands to reason that any two views will have much in common. Helping a reader of the documentation understand the relationships among views will give him a powerful insight into how the architecture works as a unified conceptual whole. Being clear about the relationship by providing mappings between views is the key to increased understanding and decreased confusion.
For instance, each module may map to multiple runtime elements, such as when classes map to objects. Complications arise when the mappings are not one to one, or when runtime elements of the system do not exist as code elements at all, such as when they are imported at runtime or incorporated at build or load time. These are relatively simple one- (or none-) to- many mappings. In general, though, parts of elements in one view can map to parts of elements in another view.
It is not necessary to provide mappings between every pair of views. Choose the ones that provide the most insight.
The element list is simply an index of all of the elements that appear in any of the views, along with a pointer to where each one is defined. This will help stakeholders look up items of interest quickly.
The glossary lists and defines terms unique to the system that have special meaning. A list of acronyms, and the meaning of each, will also be appreciated by stakeholders. If an appropriate glossary already exists, a pointer to it will suffice here.